Publish to pypi

[Chetic]

1. The current pyproject.toml is only 9 lines — it's missing:
   [build-system] section (no build backend specified at all)
   version field
   readme reference
   dependencies (currently only in requirements.txt)
   classifiers, keywords, urls
2. No Proper Package Structure
   Python modules (chunksilo.py, index.py, cfgload.py, etc.) sit at the repo root with no init.py
   No src/ layout or setuptools package discovery config
   PyPI needs to know what to actually include in the distribution
3. No Version in Python
   Version is tracked via git tags only (currently v1.8.1)
   No version attribute or dynamic version config for the build system to pick up
4. No Entry Point
   No [project.scripts] console script defined — users wouldn't have a chunksilo command after pip install
5. No PyPI Publish Workflow
   CI creates GitHub releases with bundled tar.gz archives but has no twine upload or trusted publisher step
6. 100mb limit means models can't be batteries-included-included